1. Field of the Disclosure
The instant disclosure relates to a radio frequency (RF) power amplifier; in particular, to a RF power amplifier which compensates an output power with an output current.
2. Description of Related Art
The latest concept in mobile phone designing not only focuses on a power added efficiency (PAE) along with the most output power, but also emphasizes on a high PAE in whether a high, medium, or low output power modes to offer a longer talking duration. After appropriately adjusting a gain of an output power of a power amplifier (PA), an output power ability, and linearity of a previous-stage power amplifier (PA), it is not only able to reduce an average current consumption, but also able to extend a talking duration. In prior arts, after a DC-to-DC converter is adopted with the PA, it is not only resulted in a lower power consumption at high output power, but also a low power consumption in the middle or low output power mode, and the PAE of the overall output power is increased.
A traditional switch mode power amplifier applied into 3G/4G wireless system may have provided an effective usage; however, given a demand of longer talking duration coming from consumers, and an objective to achieve the higher efficiency and lower power consumption in the middle/low output power mode, there is still improvement to be made.